Add a count parameter to CommentListing
Huge initial refactoring attempt

- Move Loader logic out of adapters and most fragment logic into a
  separate controller class to keep adapters and fragments cleaner.

- Move out fetching of content out of the provider and into the loaders.
  The ContentProvider can only do its CRUD operations.

There is probably some unnecessary code that was added due to the huge
undertaking. It's going to take a while to clean this all up.
Remove unused title and url arguments
Shorten name of CommentListFragmentController
More refactoring madness...

...it compiles. I think everything is broken though. The idea here is
to move the network logic out of the providers into the loaders and to
move the loader and fragment logic out of the adapters and into
controller classes. Things will be broken for a while, but at least, we
can sort of iterate now.